WO1999040138A1

WO1999040138A1 - Method for producing soft and elastic, semi-hard or hard moulded bodies of polyurethane free from fluorochlorohydrocarbon and having a cellular core as well as a compacted side area

Info

Publication number: WO1999040138A1
Application number: PCT/EP1999/000471
Authority: WO
Inventors: Peter Horn; Hansjoachim Scupin; Edmund Stadler; Dieter Tintelnot; Ulrich Treuling
Original assignee: Basf Aktiengesellschaft
Priority date: 1998-02-07
Filing date: 1999-01-26
Publication date: 1999-08-12
Also published as: EP1053269A1; AU2830099A; EP1053269B1; DE19804911A1; DE59904844D1

Abstract

The present invention relates to a method for producing soft and elastic, semi-hard or hard moulded bodies of polyurethane which are fluorochlorohydrocarbon-free and have a cellular core as well as a compacted side area. This method comprises reacting a) polyisocyanates with b) at least one compound having at least two reactive hydrogen atoms, with c) foaming agents, with d) catalysts and with e) optional auxiliary agents and/or additives. This method is characterised in that the foaming agents c) contain c1) at least one carbodiimide-forming catalyst and c2) at least one carboxylic acid and/or the anhydride thereof.

Description

Process for the production of chlorofluorocarbons-free, soft-elastic, semi-hard or hard polyurethane moldings with a cellular core and a compressed edge zone

description

The invention relates to a process for the production of chlorofluorocarbons-free soft-elastic, semi-hard or hard polyurethane moldings with a cellular core and a compressed edge zone by reacting

a) with polyisocyanates

b) at least one compound with at least two reactive hydrogen atoms,

c) blowing agents,

d) catalysts and optionally

e) auxiliaries and / or additives,

characterized in that the blowing agents c)

cl) at least one carbodiimide-forming catalyst, in particular a phosphorus-containing carbodiimide-forming catalyst,

c2) contain at least one carboxylic acid and / or its anhydride.

Flexible, semi-hard or hard molded polyurethane bodies with a cellular core and a compressed edge zone, also referred to as integral polyurethane foams, have long been known and have been described many times in the literature.

A comprehensive overview of such connections can be found, for example, in the Plastics Handbook, Volume 7, Polyurethane, edited by Dr. Günter Oertel, Carl-Hanser-Verlag Munich Vienna, 3rd edition, 1993, pages 355 to 415.

In the past, fluorochloroalkanes, such as trichlorofluoromethane, were used as blowing agents in the production of the integral polyurethane foams, which initially evaporate under the influence of the exothermic polyaddition reaction, then partially at elevated pressure on the cooler inner wall of the mold 2 condensed and stored in the molded body .. These blowing agents led to integral polyurethane foams with excellent properties. However, due to their high 0zone degradation potential, such blowing agents may no longer be used. To reduce the fluorochloroalkanes was used as

Blowing agents are predominantly water that reacts with the isocyanate groups to form carbon dioxide, which acts as the actual blowing agent. A disadvantage of this process, however, is that the carbon dioxide does not condense on the inner surface of the mold under the reaction conditions prevailing in the mold, and this can result in the formation of integral polyurethane foams with a pore-containing surface.

To eliminate these disadvantages, the use of porous materials in the production of integral polyurethane foams has been described in DE-A-1 804 362 integral polyurethane foams, the production of integral polyurethane foams with the use of alkali aluminum silicates or organic, hydrated water containing compounds described. This is intended to produce shrink-free molded articles with a total density of 120 g / 1.

The production of integral polyurethane foams with the use of zeolite compounds is described in EP-A-319 866 or DE-A-40 34 082, the use of silica gel in

US-A-4, 518, 718 and the use of activated carbon in EP-A-545 175.

EP-A-364 854 describes a process for producing integral polyurethane foams in which hydrocarbons, in particular n-pentane, are used as blowing agents. Because of the low flash point of the blowing agents described there, their use is associated with safety risks. The same also applies to the use of tertiary alcohols as blowing agents, as described for example in DE-A-40 20 079.

EP-A-121 850 describes a process for the production of cell-containing polyurethanes, in which amine-carbon dioxide adducts which are liquid at 20 ° C. are used as blowing agents. A disadvantage here is the short start time of these systems.

The use of carboxylic acids as blowing agents for polyurethane foams is also known. For example, EP-A-476 337 describes a combination of water and carboxylic acids and EP-A-409 199 describes mixtures of halogen-containing hydrocarbons, water and carboxylic acids as blowing agents for rigid foams. In EP-A-372 292 3 proposed the aqueous carboxylic acids, especially lactic acid as blowing agents for hard integral foams. EP-A-614 931 also proposes carboxylic acids, for example malonic acid, maleic acid, fumaric acid or citric acid, and their esters and salts, in particular ammonium salts, as blowing agents for producing polyurethane foam moldings with a compact surface. However, the use of these carboxylic acids also has disadvantages: when using oxalic acid, toxic carbon monoxide is produced, when using lactic acid, only foams with a high density can be produced, malonic acid acts as a breath poison and must therefore be handled carefully. In addition, the use of carboxylic acids described in EP-A-614 931 leads to an insufficient propelling effect.

EP-A-403 066 describes a process for the production of integral polyurethane foam in the presence of carbodiimide catalysts, in particular oxophospholenes. Carbodiimide formation can reduce the amount of chlorofluorocarbons, but the use of chlorofluorocarbons is still necessary.

EP-A-500 214 describes a process for the production of integral polyurethane foam in which phospholene oxides are used as catalysts and water and chlorofluorocarbons as blowing agents are avoided as far as possible. The polyol component contains at least 25% isocyanate-reactive compounds that contain imino or enamino groups. Long-chain carboxylic acids and their anhydrides can also be used as catalysts for the reaction of amino groups and isocyanate groups. However, the use of compounds with imino or enamino groups has disadvantages. Such compounds are very complex to manufacture and are very sensitive to hydrolysis, especially in the high amounts used according to EP-A-500 214.

EP-A-590 638 describes the production of rigid polyurethane polycarbodiimide foams which are applied by spraying. Phenol-formaldehyde resins are used as the polyol component. The blowing agent is carbon dioxide, which arises from the reaction of the isocyanates with the phenol-formaldehyde resins, the carbodiimide reaction and, if appropriate, the use of water. As carbodiimide catalysts, which are used in addition to isocyanurate and urethane catalysts, organic phosphorus compounds, such as phosphorus oxides, are proposed, among others. However, the short-chain phenol-formaldehyde resins described split off phenol under the reaction conditions of polyurethane formation, which is harmful to health is questionable. 4

In EP-A-381,324 a catalyst system comprising a Carbodiimi ^'d- catalyst and a trimerization catalyst is described. Phospholene oxides are used as carbodiimide catalysts. The blowing agents released are the carbon dioxide released in the carbodiimide reaction and, if appropriate, water and halogenated hydrocarbons.

DE-A-28 01 701 describes a process for the preparation of polyamides and polyamide imides from isocyanates and carboxylic acids and / or carboxylic anhydrides, in which cyclic phosphorus compounds are used as catalysts.

In the production of integral polyurethane foams, however, the sole use of carbodiimide catalysts as blowing agents leads to the formation of a porous skin, which is regarded as a lack of quality.

An open-cell polycarbodiimide-polyisocyanurate foam is described in US Pat. No. 5,214,076, in which aromatic polyester alcohols are used as the polyol component and water is used as the sole blowing agent. Cyclic phosphole oxides or potassium carboxylates are proposed as oligomerization catalysts. When using potassium carboxylates, the use of carboxylic acids is recommended, because otherwise the foam can crack due to the high rate of foaming.

The object of the present invention was to develop a process for the production of integral polyurethane foams which does not require the use of chlorofluorocarbons and, if possible, the use of water and combustible hydrocarbons as blowing agents, to give moldings with an integral density distribution and leads to a non-porous surface.

The object was surprisingly achieved in that the blowing agents contain at least one phosphorus-containing, carbodiimide-forming catalyst and at least one carboxylic acid and / or its anhydride.

The invention accordingly relates to a process for the production of chlorofluorocarbons-free soft-elastic, semi-hard or hard molded polyurethane bodies with a cellular core and a compressed edge zone by reacting 5 a) polyisocyanates

b) at least one compound with at least two reactive hydrogen atoms

c) blowing agents

d) catalysts and optionally

e) auxiliaries and / or additives,

characterized in that the blowing agents c)

c2) contain at least one carboxylic acid and / or its anhydride.

If appropriate, water can also be added in small amounts as a blowing agent, generally in a maximum amount of 0.3% by weight, based on the sum of components b) to e). This amount is normally entered into the reaction mixture due to the technologically determined water content of the polyols.

Physical blowing agents can also be used for certain areas of application, whereby the use of chlorofluorocarbons (CFCs) is excluded.

As phosphorus-containing, carbodiimide-forming catalyst, preference is given to using those compounds which are customary and customary for this purpose in polyurethane chemistry. According to the invention, they are preferably used in an amount of 0.1 to 4.0% by weight, based on the sum of components b) to e).

In particular, these are phosphorus-containing five-membered heterocyclic compounds of the general formulas I and II, where R2

>

/

Ri - P

Λ ^c ^ ^• \ R ₄

V \ \

Re R ₇ R ₅

X sulfur or especially oxygen

R 1 is a substituted or unsubstituted C _x to C _y alkyl, phenyl, naphthyl or benzyl group, in particular phenyl or methyl,

R ₂ , R ₃ , R ₄ , R ₅ , R _δ and R ₇ independently of one another are hydrogen,

Halogen or a Ci to C ₄ alkyl group. Such compounds are described for example in US-A-3, 657, 161, column 4, line 41 to column 5, line 3.

Such compounds are known and are described, for example, in GM Kosolapoff, L. Maier, Organic Phosphorous Compounds, Wiley-Interscience, New York, 1972, vol. 3, pages 370-371, 458 to 463 and vol. 4, pages 9, 10 and 48, as well as in US-A-2, 663, 737,

2,663,738, 2,663,739, 2,941,966 and 2,853,473. Examples include 1-methyl-loxophospholine, 1-ethyl-loxophospholine, 1-butyl-loxophospholine, 1- (2-ethylhexyl) -1-oxophospholine, 1-methyl-l-thiophospholine, 1- (2-chloroethyl-l- oxophospholine, 1-phenyl-l-oxophospholine, 1-p-tolyl-l-oxophospholine, 1-1 — chloromethyl-1-oxophospholine, 1, 3-dimethyl-l-oxophospholine, 1,2-dimethyl 1-oxophospholine, l-methyl-3-chloro-l-oxophospholine, l-methyl-3-bromo-l-oxophospholine, 1-chlorophenyl-l-oxophospholine, 1,3, 4-trimethyl-l-oxophospholine, 1, 2,4-trimethyl-l-oxophospholine, 1,2,2-trimethyl-l-oxo-phospholine, 1-phenyl-l-thiophospholine, l-phenyl-3-methyl-l-oxophospholine, l-phenyl-2, 3-dimethyl-l-oxophospholine.

Compounds with a double bond in the 2,3- or 3,4-position are preferred. They are mostly used in the form of technical mixtures of the compounds I to II.

In particular, the phosphorus-containing carbodiimide catalyst is selected from the group consisting of 1-methyl-3-phospholene-1-oxide, 3-methyl-3-phenylphosphole oxide, 3-methyl-1-benzylphosphole oxide, 3-methyl-1-ethyl phospholene oxide, l-methyl-3-phospholene 7

1-oxide and l-methyl-2-phospholen-1-oxide and mixtures of the compounds mentioned with one another.

Instead of or in particular together with the cyclic. Phosphorus-containing carbodiide catalysts of the general formulas I to II, other carbodiimide catalysts can also be used, for example diphenylphosphinic acids and their salts, bis- (2, 4, 4,, -trimethylpentyl) phosphinic acid, tributylphosphine, triisobutylphosphine sulfide, trialkylphosphine oxides how

10 trioctylphosphine oxide or trihexylphosphine oxide, triphenylphosphine, tetraphenylphosphine bromide, tetrabutylphosphine chloride, tetrabutylphosphine bromide, bis- (2, 4, 4-trimethylpentyl) dithiophosphonic acid, bis- (2,4, 4-trimothiophonic acid), and high-stero-pentylphonic acid hindered phosphine oxides.

15

Such phosphoric acid compounds are described, for example, in "International Association for Pure and Applied Chemistry, Kortüm, Vogel and Andrussow, London, Butterworths, 1961, pages 474 to 492.

20th

Carboxylic acids, polycarboxylic acids, and / or their intermolecular and / or intramolecular anhydrides and / or their amides or imides are used as blowing agent component c2).

25 The carboxylic acids can be saturated or unsaturated and mono- or polyvalent. It is also possible to use mixtures of these acids.

The acids are preferably used in an amount of 1 to 30 10% by weight, based on the sum of components b) to e).

It has proven to be advantageous to use carboxylic acids which are substituted in the α, β or γ position to the carboxyl group

35 are. Substituents with a negative inductive effect, such as halogen atoms, nitro groups, amino groups, methoxy groups, keto groups, phenyl groups, trifluoromethyl groups, acetyl groups, benzoyl groups, phenacetyl groups, nitrile groups, hydroxyl groups and trialkylammonium groups, can be used here

40 also those with a positive inductive effect, in particular C 1 -C 4 -alkyl groups, such as methyl groups, ethyl groups, isopropyl groups, are used.

Particularly suitable are those carboxylic acids and polyoxycarboxylic acids which decompose in the reaction with isocyanate groups into carbon dioxide, water and optionally olefin. 8th

Examples of saturated monocarboxylic acids are acetic acid, propionic acid, 3-hydroxypropionic acid, butyric acid, n-valeric acid, methyl ethyl acetic acid, diethyl acetic acid, ethyl dimethylacetic acid, isopropyl methyl acetic acid, isoamyl acetic acid, α-methyl hexanoic acid, butyl ethyl acetic acid, -Methyl-butyric acid, ß-methyl-butyric acid, isobutyric acid,, ß-dimethyl-butyric acid, α, α-dimethylacetylacetic acid, 2-chloropropionic acid, 3-chloropropionic acid, ß-phenyl-propionic acid, benzoylacetic acid, cyclopropanecarboxylic acid, -amino acetic acid -Acid, ot-aminoiso-caproic acid, α-amino-ß-methyl-n-valeric acid, monochloroacetic acid, dichloroacetic acid 3-hydroxypropionic acid,, ß-aminopropionic acid, α-chlorobutyric acid, ß-chlorobutyric acid γ-chlorobutyric acid, ß-oxy-butyric acid, ß-bromo-propi ononic acid, γ-bromo-butyric acid, glycolic acid, γ-oxy-butyric acid, lactic acid, glyceric acid, γ-chloro-valeric acid, γ-hydroxy-valeric acid, ß-hydroxy-propionic acid, γ-hydroxy-butyric acid, δ-hydroxy-valale- rianic acid, trimethylglycine, ß-amino-propionic acid, γ-amino-butteric acid, δ-amino-valeric acid, furilic acid, hippuric acid, pantothenic acid, α-keto-propionic acid, α-amino-ethyl glycolic acid, ß-oxy-iso - Butyric acid, acetoacetic acid, trimethylacetic acid, acetylpyruvic acid, isopropylacetic acid, stearyldiketene, ε-keto acids, γ- and δ-keto acids, monoiodoacetic acid.

The acids mentioned are mostly liquid at room temperature and can be added to the polyol and / or isocyanate component in this form. Acids which are solid at room temperature can be dissolved in polyols, in particular the low-viscosity chain extenders and or crosslinking agents or, if such substances are used in the production of the polyurethanes, inert plasticizers, and this solution can be added to at least one of the reaction components, in particular the A component.

Instead of or in a mixture with the acids mentioned, their intermolecular anhydrides can also be used.

Associations of ε-caprolactam and diols and / or polyols which have been liquid at room temperature have proven to be suitable solvents for the acids mentioned and their intermolecular anhydrides.

The acids can also be used in the form of their salts. Ammonium salts, betaines and the alkali and alkaline earth metal salts of carboxylic acids are particularly suitable. As is known, the ammonium salts of the carboxylic acids are prepared by reacting the carboxylic acids with ammonia. Mixtures formed when using a stoichiometric excess of acid 9

Ammonium salts and free acids can also be used according to the invention. The advantage of such mixtures is that the dissociation of the salts is suppressed. The ammonia generated during the foaming reaction acts as an additional blowing agent. Instead of ammonium salts, the salts of tertiary amines can also be used. Under the conditions of the foaming, the tertiary amine forms, which acts as a catalyst for the polyurethane reaction.

Even when using alkali and alkaline earth metal salts of the carboxylic acids according to the invention, it is advantageous to set an excess of free acid. The molar ratio of salt to free acid is preferably about 1: 1.2 to 1: 1.8. The acids are released from the salts mentioned by adding an acid with a lower pKa value.

The saturated monocarboxylic acids according to the invention also include homopolymers, copolymers and graft polymers with olefinically unsaturated carboxylic acids. Such compounds are described for example in EP-A-711 799. The homopolymers are polymers of olefinically unsaturated carboxylic acids and / or their anhydrides with one another. Copolymers are polymers of olefinically unsaturated monocarboxylic acids with carboxyl-free, olefinically unsaturated monomers. The olefinically unsaturated monocarboxylic acids here are preferably those having 3 to 8 carbon atoms, in particular acrylic acid, methacrylic acid, direthylacrylic acid, ethylacrylic acid, allylacetic acid and vinyl acetic acid. Preferred olefinically unsaturated dicarboxylic acids are maleic acid and fumaric acid. Preferred carboxyl-free, olefinically unsaturated monomers are vinyl ethers.

Polymers made from unsaturated carboxylic acids are preferably added to the isocyanate component. Examples include polyacrylic acid and polymethacrylic acid. Because of the high molecular weight of these polymers, their carboxyl group content is low.

Ethylenically unsaturated carboxylic acids and / or their inter- or intramolecular anhydrides can also be used as the acid component. Monoethylenically unsaturated monocarboxylic acids with 3 to 10 carbon atoms are suitable. α, β-Unsaturated monocarboxylic acids can easily be prepared by splitting off hydrogen halide from β-halocarboxylic acids, by dehydrating β-hydroxy acids or by deaminating β-amino acids. Examples include acrylic acid and methacrylic acid, β, β-dimethylacrylic acid, glutaconic acid, ethyl acrylic acid, allylacetic acid, vinyl acetic acid, n-crotonic acid, isocro- 10 Clay acid, aconitic acid, cinnamic acid, maleic ^'acid Trimethylacrylsäure, fumaric acid, mesaconic acid, methylenemalonic acid, citraconic acid, itaconic acid. Examples of anhydrides of ethylenically unsaturated carboxylic acids are maleic anhydride, benzoxazines, such as isatoic anhydride. Anhydrides which are prepared from ethylbenzene and maleic anhydride are preferably used. The number of maleic anhydride units is preferably 3 to 4. Basic or acidic amino acids are also suitable.

Suitable aromatic carboxylic acids are, for example, salicylic acid, 4-amino-salicylic acid, 3-methoxy-2-methylol-benzoic acid, p-aminobenzoic acid.

Saturated dicarboxylic acids, their anhydrides and polyhydric hydroxycarboxylic acids are also suitable. Also suitable are intramolecular anhydrides of aliphatic and / or aromatic carboxylic acids, which may also contain a free carboxyl group.

Examples of dicarboxylic acids and their compounds are succinic acid, glutaric acid, adipic acid and their intramolecular anhydrides, ethylene oxalate, mono- or dialkylmalonic acid esters, acetylenedicarboxylic acid, methylmalonic acid, diglycolic acid, dimethylmalonic acid, ethylmalonic acid, methyl succinic acid, phtaletic acid, phthalic acid acid, pyruvic acid, tartronic acid, p-tert. -Butylbenzoesäure, hydroxymalonic, 2, 3-dihydroxysuccinic acid, malic acid, tartaric acid, dihydroxyfumaric acid, dihydroxymaleic acid, Mesowein- acid, acetonedicarboxylic acid, mesoxalic acid, Mesoxalsäurehydrat, thiomalic acid, tricarballylic acid, citric acid (hydrate), hydro- xyfumarsäure, hydroxymaleic acid, oxaloacetic acid, quinic acid, shikimic acid, D-sugar acid, D-mannosugaric acid, mucic acid, D-gluconic acid, D-mannonic acid, aspartic acid, glutamic acid, tetrahydrophthalic acid, ascorbic acid, α-D-galacturonic acid, diethylmalonic acid, mandelic acid, phenylmonic acid, trimesic acid, trimellitic acid, gallic acid, pyromellophanic acid, pyromellophanic acid, pyromellophanic acid , Mellitic acid, anthranilic acid,, phenylmalonic acid, phenylsuccinic acid, benzylsuccinic acid, o., Α-dibenzyl-succinic acid. Phenylalanine, benzilic acid, tyrosine, dihydroascorbic acid, cyauric acid, trans-cyclohexane-l, 2-dicarboxylic acid, ice-cyclohexane-1, 2-dicarboxylic acid, trans-cyclohexane-1, 4-dicarboxylic acid, cis-cyclohexane-1 , 4-dicarboxylic acid. As stated above, the acids can also be used in the form of their inter- and intramolecular anhydrides. The carboxylic acids mentioned are described in Landolt-Börnstein, 1960, pages 847 to 857. Other aromatic di-, tri- and 11 tetrafunctional acids and their inter- and intramolecular anhydrides are described for example in DE-A-28 01 701. The acids and / or their anhydrides, which can optionally be substituted by OH, SH, or NH groups, are preferably added to the polyol component. Tetrafunctional carboxylic acids or their intramolecular anhydrides are not preferred for the process according to the invention. However, these compounds can be interesting in certain cases after chemical modification. For example, an intermolecular anhydride can be produced from trimellitic acid 1,2-anhydride. Furthermore, intermediate products suitable for the process according to the invention can be prepared from trimellitic acid 1,2-anhydride with glycols, glycolic acid, glycerol and trifunctional polyols by modifying the carboxyl groups. The two anhydride groups can also be reacted with aliphatic and / or aromatic amines to give amides or imides. Polyetheramines, for example, can be used as amines. It is also possible to use aliphatic diamines with 2 to 6 carbon atoms and / or alkanolamines and / or p-aminobenzoic acid as modifiers.

Another possibility for modification is the ring opening of intramolecular dianhydrides.

a) Suitable organic polyisocyanates are the known aliphatic, cycloaliphatic, araliphatic and preferably aromatic polyvalent isocyanates.

The following may be mentioned by way of example: alkylene diisocyanates having 4 to 12 carbon atoms in the alkylene radical, such as 1,12-dodecanedisoisocyanate, 2-ethyl-tetramethylene-diisocyanate-1, 4, 2-methyl-pentamethylene-diisocyanate-1, 5, 1,4-tetramethylene diisocyanate and preferably 1,6-hexamethylene diisocyanate - cycloaliphatic diisocyanates such as cyclohexane-1, 3- and -1, 4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3, 3rd , 5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate), 2,4- and 2,6-hexahydrotoluylene di-isoeyanate and the corresponding isomer mixtures, 4,4'-, 2,2'- and 2,4 '-Dicyclohexylmethane diisocyanate and the corresponding isomer mixtures, araliphatic diisocyanates such as m-, p-xylylene diisocyanate and xylylene diisocyanate isomers, and preferably aromatic di- and polyisocyanates such as 2,4- and 2, 6-tolylene diisocyanate and the corresponding isomer mixtures, 4,4'-, 2,4'- and 2,2'-diphenylmethane diisoeyanate and di e corresponding isomer mixtures, mixtures of 4,4'- and 2,4'-diphenylmethane diisocyanates, polyphenyl-polymethylene polyisocyanates, mixtures of 12

4,4'-, 2,4'- and 2, 2 'diphenylmethane diisocyanates and ^Pol' tolylene diisocyanates y- phenyl-polymethylene polyisocyanates (crude MDI), mixtures of crude MDI and 1,4- and 1, 5-naphthylene diisocyanate, 3, 3 '-dimethyl-diphenyl-4, 4' -diisocyanate, 1,2-diphenylethane diisocyanate and phenylene diisocyanate. The organic di- and polyisocyanates can be used individually or in the form of mixtures.

So-called modified polyvalent isocyanates, i.e. Products obtained by chemical reaction of organic di- and / or polyisocyanates are used. Examples of di- and / or polyisocyanates containing ester, urea, biuret, allophanate, carbodiimide, isocyanurate, uretdione, urethonimine and / or urethane groups. In particular, the following may be considered:

Organic, preferably aromatic polyisocyanates containing urethane groups with NCO contents of 33.6 to 15% by weight, preferably 31 to 21% by weight, based on the total weight, for example with low molecular weight alkanol diols, triols, dialkylene glycols, trialkylene glycols or polyoxy- alkylene glycols with molecular weights up to 6,000 modified 4,4'-diphenylmethane diisocyanate, modified 4,4'- and 2,4'-diphenylethane-diisocyanate mixtures, or modified crude MDI or 2,4- or 2,6-toluene diisocyanate, the following being, for example, di- or polyoxyalkylene glycols which can be used individually or as mixtures: diethylene glycol, dipropylene glycol, polyoxyethylene glycol, polyoxypropylene glycol and polyoxypropylene polyoxyethylene glycols, triols and / or tetrols. Prepolymers containing NCO groups with NCO contents of 14 to 1.5% by weight, preferably 8 to 2.5% by weight, based on the total weight, produced from the polyester and / or described below are also suitable preferably polyether polyols and 1,4- and 1,5-naphthylene diisocyanate, 3, 3 '-dimethyl-diphenyl-4, 4' -diisocyanate, 1, 2-diphenylethane diisocyanate, phenylene diisocyanate and

4,4'-diphenylmethane diisocyanate, mixtures of 2,4'- and 4,4'-diphenylmethane diisocyanate, 2,4- and / or 2,6-tolylene diisocyanates or crude MDI. Liquid carbodiimide groups and / or isocyanurate ring-containing polyisocyanates with NCO contents of 33.6 to 15, preferably 31 to 21% by weight, based on the total weight, for example based on 4,4'-, 2,4, have also proven useful '- and / or 2, 2' -diphenylmethane diisocyanate and / or 2,4- and / or 2,6-tolylene diisocyanate. 13

The modified polyisocyanates can be used together or with unmodified organic polyisocyanates such as e.g. 2,4'-, 4, 4'-diphenylmethane diisocyanate, crude MDI, 2,4- and / or 2,6-tolylene diisocyanate are optionally mixed.

Organic polyisocyanates have proven particularly useful and are preferably used for the production of cellular elastomers: prepolymers containing NCO groups with an NCO content of 14 to 9% by weight, in particular based on polyether or polyester polyols and one or several diphenylmethane diisocyanate isomers, advantageously 4,4'-diphenylmethane diisocyanate and / or modified urethane groups containing organic polyisocyanates with an NCO content of 33.6 to 15% by weight, in particular based on 4,4'-diphenylmethane diisocyanate or diphenylmethane diisocyanate isomer mixtures, for the production of flexible polyurethane foams: mixtures of 2,4- and 2,6-tolylene diisocyanates, mixtures of tolylene diisocyanates and crude MDI or in particular mixtures of the aforementioned prepoly - Mers based on diphenylmethane diisocyanate isomers and crude MDI and for the production of rigid polyurethane or polyurethane polyisocyanurate foam open: raw MDI.

As compounds b) having at least two reactive hydrogen atoms, those having a functionality of 2 to 8, preferably 2 to 6 and a molecular weight of 500 to 9,000 are advantageously used. Have proven successful Polyether polyamines and / or preferably polyols selected from the group of polyether polyols, polyester polyols, polythioether polyols, hydroxyl group-containing polyester amides, hydroxyl group-containing polyacetals and hydroxyl group-containing aliphatic polycarbonates or mixtures of at least two of the polyols mentioned. Polyester polyols and / or polyether polyols are preferably used.

Suitable polyester polyols can be prepared, for example, from organic dicarboxylic acids with 2 to 12 carbon atoms, preferably aliphatic dicarboxylic acids with 4 to 6 carbon atoms and polyhydric alcohols, preferably diols with 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms. Examples of suitable dicarboxylic acids are: succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used both individually and in a mixture with one another. Instead of the free dicarboxylic acids, the corresponding 14 suitable dicarboxylic acid derivatives, such as, for example, dicarboxylic acid monoesters and diesters of alcohols having 1 to 4 carbon atoms or dicarboxylic acid anhydrides. Dicarboxylic acid mixtures of succinic, glutaric and adipic acid are preferably used in proportions of, for example, 20 to 35: 35 to 50: 20 to 32 parts by weight, and in particular adipic acid. Examples of dihydric and polyhydric alcohols, especially alkanediols and dialkylene glycols are: ethanediol, diethylene glycol, 1,2- or 1,3-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, 10-decanediol, glycerin and trimethylolpropane. Ethanediol, diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol or mixtures of at least two of the diols mentioned, in particular mixtures of 1,4-butanediol, 1,5-pentanediol and 1, are preferably used. 6-hexanediol. Polyester polyols from lactones, for example ε-caprolactone or hydroxycarboxylic acids, for example ω-hydroxycaproic acid, can also be used.

The organic, e.g. Aromatic and preferably aliphatic polycarbonic acids and / or derivatives and polyhydric alcohols without a catalyst or preferably in the presence of esterification catalysts, advantageously in an atmosphere of inert gases, such as e.g. Nitrogen, carbon monoxide, helium, argon etc. polycondensed in the melt at temperatures of 150 to 250 ° C., preferably 180 to 220 ° C., if appropriate under reduced pressure, up to the desired acid number, which is advantageously less than 10, preferably less than 2. According to a preferred embodiment, the esterification mixture is polycondensed at the above-mentioned temperatures up to an acid number of 80 to 30, preferably 40 to 30, under normal pressure and then under a pressure of less than 500 mbar, preferably 50 to 150 mbar. Examples of suitable esterification catalysts are iron, cadmium, cobalt, lead, zinc, antimony, magnesium, titanium and tin catalysts in the form of metals, metal oxides or metal salts. However, the polycondensation can also be carried out in the liquid phase in the presence of diluents and / or entraining agents, e.g. Benzene, toluene, xylene or chlorobenzene, for azeotropic distillation of the condensation water.

To prepare the polyester polyols, the organic polycarboxylic acids and / or derivatives and polyhydric alcohols are advantageously polycondensed in a molar ratio of 1: 1 to 1.8, preferably 1: 1.05 to 1.2. 15

To produce low-fogging PU moldings, the polyester polyols are expediently subjected to distillation at from 140 to 280 ° C. and under reduced pressure from 0.05 to 30 mbar, e.g. subjected to thin-layer distillation to remove volatile constituents.

The polyester polyols obtained preferably have a functionality of 2 to 4, in particular 2 to 3 and a molecular weight of 500 to 3,000, preferably 1,200 to 3,000 and in particular 1,800 to 2,500.

However, polyether polyols used in particular as polyols are those which, by known processes, for example by anionic polymerization with alkali hydroxides, such as sodium or potassium hydroxide or alkali alcoholates, such as sodium methylate, sodium or potassium ethylate or potassium isopropylate, are used as catalysts and with the addition of at least one starter molecule, the second contains up to 8, preferably 2 to 6, reactive hydrogen atoms, or by cationic polymerization with Lewis acids, such as antimony pentachloride, boron fluoride etherate and others or bleaching earth as catalysts from one or more alkylene oxides having 2 to 4 carbon atoms in the alkylene radical.

Suitable alkylene oxides are, for example, tetrahydrofuran, 1,3-propylene oxide, 1,2- or 2,3-butylene oxide, styrene oxide and preferably ethylene oxide and 1,2-propylene oxide. The alkylene oxides can be used individually, alternately in succession or as mixtures. Examples of suitable starter molecules are: water, organic dicarboxylic acids, such as succinic acid, adipic acid, phthalic acid and terephthalic acid, aliphatic and aromatic, optionally N-mono-, N, N- and N, N'-dialkyl-substituted diamines with 1 to 4 Koh - Lenomen atoms in the alkyl radical, such as optionally mono- and dialkyl-substituted ethylenediamine, diethylenetriamine, triethylenetetramine, 1,3-propylenediamine, 1,3- or 1,4-butylenediamine, 1,2-, 1,3-, 1,4-, 1,5- and 1,6-hexamethylenediamine, phenylenediamines, 2,3-, 2,4, 3,4- and 2,6-toluenediamine and 4,4'-, 2,4'- and 2,2 'diamino-diphenylmethane.

Other suitable starter molecules are: alkanolamines, such as ethanolamine, N-methyl- and N-ethylethanolamine, dialkanolamines, such as diethanolamine, N-methyl- and N-ethyl-diethanolamine and trialkanolamines such as triethanolamine and ammonia. Polyhydric, in particular di- and / or trihydric alcohols, such as ethane, are preferably used. 16 diol, propanediol-1, 2 and -1.3, diethylene glycol, dipropylene glycol, butanediol-1, 4, hexanediol-1, 6, glycerin, trimethylolpropane, pentaerythritol, sorbitol and sucrose.

The polyether polyols, preferably polyoxypropylene and

Polyoxypropylene-polyoxyethylene-polyols have a functionality of preferably 2 to 3 and in particular 2 to 2.6 and molecular weights of 1,800 to 9,000, preferably 2,000 to 6,500 and in particular 2,400 to 5,200 for the production of flexible moldings and for the production of rigid, hard moldings a functionality of preferably 3 to 8, in particular 3 to 6 and molecular weights of 500 to 2,400, preferably 600 to 1,800 and in particular 600 to 1,500 and suitable polyoxytetramethylene glycols a molecular weight of up to approximately 3,500.

Also suitable as polyether polyols are polymer-modified polyether polyols, preferably graft polyether polyols, in particular those based on styrene and / or acrylonitrile, which are obtained by in situ polymerization of acrylonitrile, styrene or preferably mixtures of styrene and acrylonitrile, e.g. in a weight ratio of 90:10 to 10:90, preferably 70:30 to 30:70, in expediently the aforementioned polyether polyols analogous to the information in German patents 11 11 394, 12 22 669 (US 3,304,273, 3,383,351, 3 523 093), 11 52 536 (GB 10 40 452) and 11 52 537 (GB 987 618), and polyether-polyol dispersions, which are used as the disperse phase, usually in an amount of 1 to 50% by weight, preferably 2 to 25% by weight, contain: e.g. Polyureas, polyhydrazides, tert. -Amino groups containing bound polyurethanes and / or melamine and the e.g. are described in EP-B-011 752 (US 4 304 708), US-A-4 374 209 and DE-A-32 31 497.

Like the polyester polyols, the polyether polyols can be used individually or in the form of mixtures. They can also be mixed with the graft polyether polyols or polyester polyols and the hydroxyl-containing polyester amides, polyacetals, polycarbonates and / or polyether polyamines.

Examples of suitable hydroxyl-containing polyacetals are the compounds which can be prepared from glycols, such as diethylene glycol, triethylene glycol, 4,4'-dihydroxyethoxydiphenyldimethylmethane, hexanediol and formaldehyde. Also through polymerisation 17 tion of cyclic acetals, suitable polyacetals can be produced.

Suitable polycarbonates containing hydroxyl groups are those of the type known per se, which can be obtained, for example, by reacting diols, such as propanediol (1,3), butanediol (1,4) and / or hexanediol (1,6), Diethylene glycol, triethylene glycol or tetraethylene glycol with diaryl carbonates, for example Diphenyl carbonate or phosgene can be produced.

The hydroxyl-containing polyester amides include e.g. the predominantly linear condensates obtained from polyvalent, saturated and / or unsaturated carboxylic acids or their anhydrides and polyvalent saturated and / or unsaturated ammo alcohols or mixtures of polyhydric alcohols and ammo alcohols and / or polyamines.

Suitable polyether polyamines can be prepared from the above-mentioned polyether polyols by known processes. Examples include the cyanoalkylation of polyoxyalkylene polyols and subsequent hydrogenation of the nitrile formed (US Pat. No. 3,267,050) or the partial or complete amination of polyoxyalkylene polyols with amines or ammonia in the presence of hydrogen and catalysts (DE 12 15 373).

Compounds b) also include difunctional chain extenders and / or trifunctional and higher-functionality crosslinking agents. To modify the mechanical properties, e.g. the hardness, the addition of chain extenders, crosslinking agents or, if appropriate, mixtures thereof may prove to be advantageous. For the production of compact and cellular PU or PU-PH elastomers, thermoplastic polyurethanes and flexible, soft-elastic PU foams, chain extenders and optionally crosslinking agents are expediently used. Diols and / or triols with molecular weights of less than 500, preferably from 60 to 300, are used as chain extenders and / or crosslinking agents

For example, dialkylene glycols and aliphatic, cycloaliphatic and / or araliphatic diols with 2 to 14, preferably 4 to 10 carbon atoms, such as, for example, ethylene glycol, 1, 3-propanediol, 1-decanediol, 10, o-, m-, p- Di-hydroxycyclohexane, diethylene glycol, dipropylene glycol and preferably butanediol-1, 4, hexanediol-1, 6 and bis- (2-hydroxyethyl) hydroquinone, triols, such as 1,2,4-, 1, 3, 5-trihydroxy - 18 cyclohexane, glycerol and trimethylolpropane and low molecular weight hydroxyl-containing polyalkylene oxides based on ethylene and / or 1, 2-propylene oxide and the abovementioned diols and / or triols as starter molecules.

For the production of cellular polyurethane (PU) -polyurea (PH) elastomers, in addition to the diols and / or triols mentioned above or in a mixture with these as chain extenders or crosslinking agents, secondary aromatic diamines, primary aromatic diamines, 3,3'-di- and / or 3,3'-,

5, 5'-tetraalkyl-substituted diamino-diphenylmethane find application.

The chain extenders and / or crosslinking agents mentioned can be used individually or as mixtures of the same or different types of compounds.

If chain extenders, crosslinking agents or mixtures thereof are used, they are expediently used in amounts of 2 to 60% by weight, preferably 8 to 50% by weight and in particular 10 to 40% by weight, based on the weight of the component ( b) for use.

c) The blowing agents c) used are the carbodimide catalysts c1) and c2) described above.

d) In particular, compounds are used as catalysts (d) for catalysing the polyisocyanate polyaddition which greatly accelerate the reaction of the compounds of component (b) and optionally (c) containing hydroxyl groups with the organic, optionally modified polyisocyanates (a). Organic metal compounds, preferably organic tin compounds, such as tin (II) salts of organic carboxylic acids, for example tin (II) diacetate, tin (II) dioctoate, tin (II) diethylhexoate and tin ( II) dialaurate and the dialkyltin (IV) salts of organic carboxylic acids, for example dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate. Zialkyltin (IV) mercapto compounds, such as bislauryltin (IV) dimercaptide, and compounds of the general formulas R ₂ Sn (SR'-0-CO-R '') ₂ or RSn (SR '-CO- OR'') ₂ , in which R is an alkyl radical with at least 8 carbon atoms, R' is an alkyl radical with at least 2 carbon atoms and R '' is an alkyl radical with at least 4 carbon atoms. Examples of catalysts of this type which are described, for example, in DD-A-218 668 are: dioctyltin bis / thioethylene glycol 2-ethyl 19 hexoate), dioctyltin bis (thioethylene glycol laurate), dioctyltin bis (2-thiolatoacetic acid, 2-ethylhexyl ester, dioctyltin bis (hexiol thiolate)) and dioctyltin bis (thiolato acetic acid also have good organochemicals as catalysts Tin-oxygen or tin-sulfur bonds, as described for example in DD-A-255 535, of the general formulas (R ₃ Sn) ₂ 0, R ₂ SnS, (R ₃ Sn) ₂ S, RSn (SR ' ) ₂ or RSn (SR ') ₃ , in which R and R' represent alkyl groups which contain 4 to 8 carbon atoms in R and 4 to 12 carbon atoms in R 'and R' also contains the radicals -R''C00R '' and -R "OCOR"", in which R" are alkyl groups with 1 to 6 carbon atoms and R "" alkylene groups with 4 to 12 carbon atoms. Examples include: bis (tributyltin) oxide, dibutyltin sulfide, Dioctyltin sulfide, bis (tributyltin) sulfide, dibutyltin bis (2-ethylhexyl thioglycolic acid), di octyltin bis (2-ethylhexyl thioglycolate), octyltin tris (2-ethylhexyl thioglycolate), dioctyltin bis (2-ethylthioethylene glycol) and dibutyltin bis (thioethylene glycol laurate).

The organic metal compounds can be used as catalysts individually or in the form of catalyst combinations. A combination which consists of di-n-octyltin bis (2-ethylhexyl thioglycolate) and mono-n-octyltin tris (2-ethylhexylthioglycolate) has proven to be extremely advantageous, advantageously in a weight ratio of 70:30 until 30:70 or 94: 6.

The organic metal compounds can be used alone or in

Combination with strongly basic amines can be used. Examples include amidines such as

2, 3-dimethyl-3, 4, 5, 6-tetrahydropyrimidine, tertiary amines, such as triethylamine, tributylamine, dirnethylbenzylamine, N-methyl-, N-ethyl-, N-cyclohexylmorpholine, N, N, N '.M'- Tetramethyl-ethylenediamine, N, N, N ', N'-tetramethyl-butanediamine, N, N, N', N'-tetramethyl-diaminodicyclohexylmethane, pentamethyl-diethylenetriamine, tetramethyl-diaminoethyl ether, bis (dimethylamino - Propyl) urea, dirnethyl piperazine, 1, 2-dimethylimidazole, 1-aza-bi-cyclo- (3, 30) -octane and preferably 1, 4-diaza-bicyclo (2,2,2) -otane and alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyl- and N-ethyl-di-ethanolamine and dimethylethanolamine. Preferred catalysts are 1-methylimidazole and alkyl-substituted imidazoles. Suitable imidazoles are described in Dissociation Constants, London Butterworths, 1965, pages 190 ff and page 87 ff. 20th

In particular, when using an excess of polyisocyanate, the following are also suitable as catalysts: tris (dialkylaminoalkyl) s-hexahydrotriazines, in particular tris (N, N-dimethylaminopropyl) s-hexahydrotriazine, tetraalkylammonium hydroxides, such as e.g. Tetramethylammonium hydroxide, alkali hydroxides, e.g. Sodium hydroxide and alkali alcoholates, e.g. Sodium methylate and potassium isopropylate, alkali formates and acetates, e.g. Potassium formate and potassium acetate as well as alkali salts of long-chain fatty acids with 10 to 20 carbon atoms and optionally pendant OH groups. 0.001 to 5% by weight, in particular 0.05 to 2% by weight, of catalyst or catalyst combination, based on the weight of component (b), are preferably used.

To produce the self-separating, compact or cellular, optionally containing reinforcing articles from polyisocyanate polyaddition products, it may be expedient to use additional auxiliaries for process engineering or system-specific reasons. For this purpose, for example, additional external and / or internal release agents, surface-active substances, foam stabilizers, cell regulators, lubricants, fillers, dyes, pigments, flame retardants, hydrolysis protection agents, fungistatic and bacteriostatic substances or mixtures thereof, and in particular for the production of moldings with a compacted edge zone and a cellular core using water as a blowing agent in a closed mold with compression microporous activated carbon and / or microporous carbon molecular sieves according to US Pat. No. 5,254,597, crystalline, microporous molecular sieves and / or crystalline silicon oxide according to US-A- 5 110 834, amorphous microporous silica gel according to EP-A-0 513 573, concentrates of polyhydroxyl compounds and ammonium carbonate and / or salts of amines and carbon dioxide.

Suitable release agents are, for example, metal salts of stearic acid which can be prepared from commercially available stearic acid and which, without the separation effect being significantly impaired, up to 10% by weight, preferably up to 5% by weight, optionally unsaturated carboxylic acids with 8 up to 24 carbon atoms, such as Palmitic acid, oleic acid, ricinoleic acid and others may contain.

As metals for the formation of the metal salts of stearic acid, for example alkali metals, preferably sodium and potassium, alkaline earth metals, preferably magnesium and calcium and in particular zinc are used. Preferably as 21

Metal salts of stearic acid, zinc stearate, calcium stearate and sodium stearate or mixtures of at least two stearates are used. In particular, a mixture of zinc, calcium and sodium stearate is used.

If the additional use of the metal salts of stearic acid as a release agent proves to be advantageous, the metal stearates are advantageously used in an amount of at least 12% by weight, preferably 0.1 to 8% by weight, based on the weight of the higher molecular weight compounds two reactive hydrogen atoms (b) are used.

Also very suitable as release agents are carboxylic acid ide and / or imides, as described in WO 97/21747.

As surface-active substances there are e.g. Compounds into consideration which serve to support the homogenization of the starting materials and, if appropriate, are also suitable for regulating the cell structure. Examples include emulsifiers such as the sodium salts of castor oil sulfates or of fatty acids and salts of fatty acids with amines, e.g. oleic acid diethylamine, stearic acid diethanolamine, ricinoleic acid diethanolamine, salts of sulfonic acids, e.g. Alkali or ammonium salts of dodecylbenzene or dinaphthylmethane disulfonic acid and ricinoleic acid; Foam stabilizers, such as siloxane-oxalkylene copolymers and other organopolysiloxanes, ethoxylated alkylphenols, ethoxylated fatty alcohols, paraffin oils, castor oil or ricinoleic acid esters, turkish red oil and peanut oil and cell regulators, such as paraffins, fatty alcohols and dimethylpolysiloxanes. Oligomeric polyacrylates with polyoxyalkylene and fluoroalkane residues as side groups are also suitable for improving the emulsifying action, the cell structure and / or stabilizing the foam. The surface-active substances are usually used in amounts of 0.01 to 5 parts by weight, based on 10 parts by weight of component (b).

The addition of a ricinoleic acid polyester with a molecular weight of 1,500 to 3,500, preferably 2,000 to 3,000, has proven particularly useful as a lubricant, and is advantageously in an amount of 0.5 to 10% by weight, preferably 5 to 8% by weight. -%, based on the weight of component (b) or components (b) and (c) is used.

Fillers, in particular reinforcing fillers, are to be understood as the conventional organic and inorganic fillers and reinforcing agents known per se. in the 22 individual substances are mentioned as examples: inorganic fillers, such as glass balls, silicate minerals, for example layered silicates such as antigorite, serpentine, hornblende, amphibole, chrisotile, talc, wollastonite, mica and synthetic silicates such as magnesium aluminum silicate (Transpafill®); Metal oxides such as kaolin, aluminum oxides, aluminum silicate, titanium oxides and iron oxides, metal salts such as chalk, heavy spar and inorganic pigments such as cadmium sulfide and zinc sulfide. Examples of suitable organic fillers are carbon black, melamine, rosin, cyclopentadienyl resins and graft polymers. The fillers can be used either individually or in suitable combinations with one another or with one another. Fillers can also be used in conjunction with reinforcing agents.

The inorganic and / or organic fillers can be incorporated into the reaction mixture, and if they are used at all, advantageously in an amount of 0.5 to 50% by weight, preferably 1 to 40% by weight, based on the Weight of components (a) to (c) are used.

Suitable flame retardants are, for example, tricresyl phosphate, tris (2-chloroethyl) phosphate, tris (2-chloropropyl) phosphate, tris (1,3-dichloropropyl) phosphate, tris (2,3-dibromopropyl) phosphate and tetrakis (2-chloroethyl) ethylene diphosphate.

More detailed information on the other customary auxiliaries and additives mentioned above can be found in the specialist literature, for example the monograph by J.H. Saunders and K.C. Frisch, "High Polymers", Volume XVI, Polyurethanes, Parts 1 and 2, Verlag Interscience Publishers 1962 and 1964, respectively, or the Kunststoff-Handbuch, Polyurethane, Volume VII, Carl-Hanser-Verlag, Munich, Vienna, 1st, 2nd and 3rd edition, 1966, 1983 and 1993.

To produce the compact or cellular moldings, the organic, optionally modified polyisocyanates (a), compounds having at least two reactive hydrogen atoms (b) can be reacted in amounts such that the equivalence ratio of NCO groups of the polyisocyanates (a) is used Sum of the reactive hydrogen atoms of component (b) is 0.85 to 1.50: 1, preferably 0.95 to 1.15: 1 and in particular 1.0 to 1.1: 1. 23

The cellular molded articles according to the invention made of polyisocyanate polyadducts can be prepared by the prepolymer process or preferably by the one-shot process with the aid of low-pressure technology or high-pressure technology, preferably in closed, suitably temperature-controlled molds, for example metallic molds, e.g. made of aluminum, cast iron or steel or molds made of fiber-reinforced polyester or epoxy molding compounds.

Cellular polyurethanes or elastomers are produced in particular by means of the reaction injection molding technique (RIM technique). These procedures are described, for example, by Piechota and Röhr in "Integralschaumstoff", Carl-Hanser-Verlag, Munich, Vienna, 1975; D.J. Prepelka and J.L. Wharton in Journal of Cellular Plastics, March / April 1975, pages 87 to 98, U. Knipp in Journal of Cellular Plastics, March / April 1973, pages 76 to 84 and in the Plastics Manual, Volume 7, Polyurethane, 2nd edition, 1983, pages 333 ff.

It has proven to be particularly advantageous to work according to the two-component process and to combine the structural components (b), (c) and (d) and (e) in component (A) and, as component (B), the organic polyisocyanates, if appropriate To use blowing agent (c).

The starting components can be mixed at a temperature of 15 to 80 ° C., preferably 20 to 55 ° C., and placed in an open or closed mold, which has previously been used as reinforcing agent for the production of reinforced moldings with fabrics, mats, felts, nonwovens and / or fabrics can be filled. To produce integral foams and cellular or compact elastomers, the reaction mixture can be introduced into the closed mold under increased pressure.

The mixing can be carried out mechanically by means of a stirrer or a stirring screw or under high pressure in the so-called countercurrent injection process. The mold temperature is advantageously 20 to 120 ° C, preferably 30 to 80 ° C and in particular 45 to 60 ° C. If the moldings are produced in a closed mold with compaction, for example to form a compact edge zone and a cellular mold core, it has proven expedient to have degrees of compaction in the range from 1.2 to 8.3, preferably 1.6 to 6.0 and in particular to apply 2.0 to 4.0. 24

The produced according to the process of this invention cellular ^'elastomers have densities of from about 0.76 to 1.1 g / cm ^3, preferably from 0.9 to 1.0 g / cm ^3, wherein the density of flüllstoff--containing and / or in particular Products reinforced with glass mats can achieve higher values, for example up to 1.4 g / cm ³ and more. Shaped bodies made of such cellular elastomers are used, for example, in the automotive industry, for example in the automotive interior as trim parts, hat racks, trunk covers, dashboards, steering wheels and headrests, and as external parts, such as rear spoilers, rain gutters and bumpers and as rollers.

The flexible, semi-hard and hard polyurethane integral foam molded articles produced by the process according to the invention have a density of 0.025 to 0.75 g / cm ³ , the densities of the PU molded foams preferably being 0.03 to 0.24 g / cm ³ and in particular 0.03 to 0.1 g / cm ³ and the densities of the PU integral foam molded articles are preferably 0.08 to 0.75. g / cm ³ and in particular 0.24 to 0.6 g / cm ³ . The PU foam and PU integral foam molded articles are used, for example, in the vehicle, for example automotive, aircraft and shipbuilding industries, the furniture and sporting goods industry, for example as upholstery materials, for example car, motorcycle or tractor seats, as headrests, trim elements , Housing parts, consoles, ski core, inner ski protection, roof frame and roof lining in means of transport and window frames.

The invention is illustrated by the examples below

Example 1 (comparison)

A component:

Mixture consisting of

79.00 parts by weight of a glycerol-started polyoxypropylene (86.0% by weight) polyoxyethylene (14% by weight) polyol with the hydroxyl number 28,

5.00 parts by weight of a graft polyether polyol with a hydroxyl number of 25, produced from a glycerol-started polyoxypropylene polyoxyethylene polyol as the graft base and a mixture of styrene and acrylonitrile in a weight ratio of 12: 8 as a graft pad (Lupranol® 4100 from BASF), 25th

8.00 parts by weight of ethylene glycol,

1.5 parts by weight of 1-methyl-imidazole,

3.5 parts by weight of 1-methyl-phospholene-l-oxide isomer mixture from Hoechst AG, Knapsack plant, Germany, (mixture of l-methyl-2-phospholene-l-oxide and l-methylene-2-phospho- len-1-oxide),

3.0 parts by weight of black paste (consisting of 30% carbon black and 70% dioctyl phthalate).

B component:

Mixture consisting of

60 parts by weight of a mixture of 50 parts by weight of 4,4'-diphenylmethane diisocyanate and 50 parts by weight of 2,4-diphenylmethane diisocyanate with an NCO content of 33.5 parts by weight. % and

40 parts by weight of a mixture containing 4,4'-, 2,2'-diphenylmethane diisocyanates and polyphenyl polymethylene polyisocyanate (= crude MDI). The total mixture of the B component has an NCO content of 32.6% by weight.

Carrying out the experiment:

100 parts by weight of the A component and 41.1 parts by weight of the B component were mixed at 22 ° C using the reaction spray process on a high-pressure metering unit of the Puromat® 80/40 type from Elastogran Polyurethan GmbH, Mechanical Engineering division, 8021 Straßbach, FRG, mixed and placed in a metal mold with the shape of a car wheel in a temperature of 45 ° C in such a quantity that a degree of compaction of 2.5 was achieved when foaming.

The molded body was removed from the mold after 3 minutes. It had a cellular core and a compact skin and an almost non-porous surface. The Shore A hardness was 51-53. A poor flow path was found during the test. In addition, it was found that an undesirable ripple occurred especially in airbag steering wheels. When the reaction mixture was foamed in an open mold, a start time of 7 seconds was obtained, the rise time was 33 seconds. The bulk density of the foam body was 198 kg / m ³ . 26

Example 2 (comparison)

A component:

Mixture consisting of

78.90 parts by weight of a glycerol-started polyoxypropylene (86.0% by weight) polyoxyethylene (14% by weight) polyol with the hydroxyl number 28,

5.00 parts by weight of a graft polyether polyol according to Comparative Example 1,

7.20 parts by weight of ethylene glycol,

1.3 parts by weight of 1-methylimidazole,

4.6 parts by weight of malic acid (50% by weight dissolved in ethylene glycol),

B component:

Analogous to example 1

Carrying out the experiment:

100 parts by weight of the A component and 47.9 parts by weight of the B component were processed into a steering wheel analogously to Comparative Example 1. The degree of compression was 2.6. The demolding time was 5 minutes. The molded body had a cellular core with a visible skin formation. The steering wheel showed a minipore surface despite the skin formation, it showed after 24

Hours the required dimensional stability. The Shore A hardness was 62-65. The flow behavior is better than in Comparative Example 1. When the reaction mixture was foamed in an open mold, a start time of 6 seconds and a rise time of 46 seconds were obtained. The bulk density of the foam body was 193 kg / m ³ . 27

Example 3 (comparison)

A component:

Mixture consisting of

78.80 parts by weight of a glycerol-started polyoxypropylene (86.0% by weight) polyoxyethylene (14% by weight) polyol with the hydroxyl number 28,

10

5.00 parts by weight of a graft polyether polyol according to Comparative Examples 1 and 2,

5, 7 parts by weight of ethylene glycol,

15

2.0 parts by weight of 1-methylimidazole,

5.5 parts by weight of citric acid (30% by weight in ethylene glycol),

20 3.0 parts by weight of black paste (consisting of 30% carbon black and 70%

Dioctyl phthalate).

B component:

25 Analogous to example 1 and 2

Carrying out the experiment:

100 parts by weight of the A component and 48.1 parts by weight of the B component were processed into a steering wheel analogously to Example 1 and Example 2. The degree of compression was 2.6. The demolding time was 4 minutes. The molded body had a cellular core with good skin formation. The flow behavior and the porosity are analogous to Example 2. The required dimensional stability after 35 24 hours is present. When the reaction mixture was foamed in an open mold, the start time was 5 seconds and the rise time was 37 seconds. The bulk density of the foam body was 194 kg / m ³ . The Shore A hardness was 57-59.

40

45 28

Example 4

A component:

I mixture consisting of

78.65 parts by weight of a glycerol-started polyoxypropylene (86.0% by weight) polyoxyethylene (14% by weight) polyol with the hydroxyl number 28,

5.00 parts by weight of a graft polyol according to Examples 1 to 3, OH number 25,

6, 35 parts by weight of ethylene glycol,

0,. 5 parts by weight of 1-methyl-phospholene-l-oxide isomer mixture from Hoechst AG, Knapsack plant, FRG, (mixture of l-methyl-3-phospholene-l-oxide and l-methyl-2-phospholene- 1-oxide),

2.0 parts by weight of 1-methyl-imidazole,

4.5 parts by weight of citric acid (30% by weight in ethylene glycol),

B component:

Analogous to example 1 to 3

Carrying out the experiment:

100 parts by weight of the A component and 47.8 parts by weight of the B component were processed into a steering wheel analogously to the comparative examples. The degree of compression was 2.7. The demolding time was 3.5 minutes. The molded body had a cellular core with good skin formation. The flow behavior was very good. The dimensional stability after 24 hours was not yet good enough for a production process. The Shore A hardness was 46 - 50. Despite the good skin formation, micropores were still present on the steering wheel in some places. When foaming in an open mold, a start time of 4 seconds and a rise time of 31 seconds were measured. The bulk density of the foam body was 184 kg / m ³ . 29

Example 5

A component:

Mixture consisting of

6, 35 parts by weight of ethylene glycol,

0.5 parts by weight of 1-methyl-phospholene-l-oxide isomer mixture from Hoechst AG, Knapsack, Germany, (mixture of l-methyl-3-phospholene-l-oxide and l-methyl-2-phospho - len-1-oxide),

2.0 parts by weight of 1-methyl-imidazole,

4.5 parts by weight of citric acid (30% by weight in ethylene glycol),

3.0 parts by weight of black paste (consisting of 30% carbon black and 70%

Dioctyl phthalate).

B component:

Mixture consisting of

75 parts by weight of a polyisocyanate mixture containing carbodiimide groups and having an NCO content of 29.5% by weight, produced by partial carbodiimidization of 4,4'-diphenylmethane diisocyanate and

25 parts by weight of a polymer which was prepared from 87.01 parts by weight of 4, 4'-diphenylmethane diisocyanate and 8.14 parts by weight of dipropylene glycol and 4.85 parts by weight of a polyoxypropylene polyol, which is mixed with 1 , 2-propylene glycol was started, with an OH number of 250, with an NCO content of 23 wt .-%. The mixture had a total NCO content of 27.8% by weight. 30th

Carrying out the experiment:

100 parts by weight of the A component and 56.3 parts by weight of the B component were processed into a steering wheel analogously to the comparative examples. The degree of compression was 2.8. The demolding time was 3 minutes. The molded body had a cellular core with good skin formation. The flow behavior was very good. The required dimensional stability was guaranteed immediately after demolding. The shrinkage after 24 hours was fine (no ripple). The Shore A hardness was 61-63. The skin was well developed, micropores were still present on the steering wheel. When foaming in an open mold, a start time of 4 seconds and a rise time of 31 seconds were measured. The bulk density of the foam body was 180 kg / m ³ .

Example 6

A component:

Mixture consisting of

79.0 parts by weight of a glycerol-started polyoxypropylene (86.0% by weight) polyoxyethylene (14% by weight) polyol with the hydroxyl number 28,

5.00 parts by weight of a graft polyol according to Example 4, OH number 25,

8.65 parts by weight of ethylene glycol,

1.7 parts by weight of 1-methyl-imidazole,

0.75 parts by weight of 1-methyl-phospholene-l-oxide isomer mixture from Hoechst AG, Knapsack plant, FRG, (mixture of l-methyl-3-phospholene-l-oxide and 1-methyl-2-phospho- len-1-oxide),

1.7 parts by weight of malic acid (50% by weight in ethylene glycol),

3.0 parts by weight of black paste (consisting of 30% carbon black and 70

Dioctyl phthalate),

0.2 parts by weight of water. 31

B component:

Mixture consisting of

5 75 parts by weight of a polyisocyanate mixture containing carbodiimide groups and having an NCO content of 29.5% by weight, produced by partial carbodiimidization of 4,4'-diphenylmethane diisocyanate and

10 25 parts by weight of a polymer which was prepared from 87.01 parts by weight of 4, 4'-diphenylmethane diisocyanate and 8.14 parts by weight of dipropylene glycol and 4.85 parts by weight of a polyoxypropylene polyol, which with 1, 2-propylene glycol was started, with an OH number of 250, with

15 an NCO content of 23 wt .-%. The mixture had a total NCO content of 27.8% by weight.

Carrying out the experiment:

20 100 parts by weight of the A component and 59.9 parts by weight of the B component were at 22 ° C by the reaction spray process on a high-pressure metering system of the type Puromat® 80/40 from Elastogran Polyurethan GmbH, Mechanical Engineering division, 8021 Straßbach, FRG, mixed and in a metallic mold tempered to 45 ° C

25 tool with the spatial shape of an automobile steering wheel in one

45 ° C tempered metal mold with the spatial shape of an automobile wheel introduced in such an amount that a degree of compression of 2.7 was established when foaming.

30 The molded body was removed from the mold after 3 minutes. It had a cellular core, a compact surface, very good skin. The required dimensional stability was guaranteed immediately after demolding. The shrinkage after 24 hours was fine (no ripple). The surface had small pores. At the

35 foaming of the reaction mixture in an open mold gave a start time of 6 seconds, the rise time was 34 seconds. The bulk density was 188 kg / m ³ . The Shore A hardness was 72-74.

40

45 32

Example 7

A component:

Mixture consisting of

79.25 parts by weight of a glycerol-started polyoxypropylene (86.0% by weight) polyoxyethylene (14% by weight) polyol with an OH number of 28,

5.00 parts by weight of a graft polyether polyol with a hydroxyl number of 25, according to Example 5,

8.10 parts by weight of ethylene glycol,

1.7 parts by weight of 1-methylimidazole,

0.75 parts by weight of a 1-methyl-phospholene-l-oxide isomer mixture from Hoechst AG, Knapsack, Germany, (mixture of l-methyl-3-phospholene-l-oxide and 1-methyl-2-phospho- len-1-oxide),

2.0 parts by weight of citric acid (30% by weight in ethylene glycol),

3.0 parts by weight of black paste (consisting of 30% carbon black and 70% dioctyl phthalate),

0.2 parts by weight of water.

B component:

According to example 6

Carrying out the experiment:

100 parts by weight of the A component and 59.9 parts by weight of the B component were at 22 ° C by the reaction spray process on a high-pressure metering system of the type Puromat® 80/40 from Elastogran Polyurethan GmbH, business unit mechanical engineering, 8021 Straßbach , FRG, mixed and introduced into a metal mold with the spatial shape of an automobile steering wheel at 45 ° C. in such an amount that a degree of compaction of 2.5 was established when foaming.

The molded body was removed from the mold after 3 minutes. It had a cellular core, a compact surface, very good skin. The required dimensional stability was immediately after demolding 33 guaranteed. The shrinkage after 24 hours was fine (no ripple). The surface had small pores. The Shore A hardness was 73-74. When the reaction mixture was foamed in an open mold, a start time of 6 seconds was obtained, the rise time was 29 seconds. The bulk density was 188 kg / m ³ .

Claims

34

claims

1. Process for the production of chlorofluorocarbons-free soft-elastic, semi-hard or hard polyurethane moldings with a cellular core and a compressed edge zone by reaction of

a) with polyisocyanates

b) at least one compound with at least two reactive hydrogen atoms,

c) blowing agents,

d) catalysts and optionally

e) auxiliaries and / or additives,

characterized in that the blowing agents c)

cl) at least one carbodiimide-forming catalyst,

c2) at least one carboxylic acid and / or its anhydride

contain.

2. The method according to claim 1, characterized in that carbodiimide-forming catalysts containing phosphorus compounds are used.

3. The method according to claim 1, characterized in that five-membered heterocyclic compounds with phosphorus as the hetero atom are used as the phosphorus-containing, carbodiimide-forming catalysts.

4. The method according to claim 1, characterized in that as phosphorus-containing, carbodiimide-forming catalysts are those of the general formulas I to II, 35 2, ^R 3? 3 R4

R ₂ ^

Ri P

R4

X x

\

R ₆ R ₇ ^R 5 Rδ R7 5

I II

in which

X sulfur or in particular oxygen,

i a substituted or unsubstituted C _x - to C _y -

Are alkyl, phenyl, naphthyl or benzyl group, in particular phenyl or methyl,

R, R ₃ , R4, R ₅ , Rs and R ₇ independently of one another are hydrogen, halogen or a C 1 -C ₄ -alkyl group,

be used.

5. The method according to claim 1, characterized in that the phosphorus-containing, carbodiimide-forming catalysts in an amount of 0.1 to 4.0 wt .-%, based on the sum of components b) to e), are used.

6. The method according to claim 1, characterized in that aliphatic monocarboxylic acids having 2 to 8 as carboxylic acids

Carbon atoms can be used.

A method according to claim 1, characterized in that aliphatic dicarboxylic acids are used as carboxylic acids.

A method according to claim 1, characterized in that aromatic carboxylic acids are used as carboxylic acids.

9. The method according to claim 1, characterized in that the carboxylic acids are substituted.

10. The method according to claim 1, characterized in that the carboxylic acids are substituted by hydroxyl or amino groups. 36

11. The method according to claim 1, characterized in that as ^' carboxylic acids are formed in situ from their ammonium, alkali or alkaline earth salts.

12. The method according to claim 1, characterized in that the

Carboxylic acids are used in the form of their intermolecular or intramolecular anhydrides.

13. The method according to claim 1, characterized in that the carboxylic acids in an amount of 0.2 to 10 wt .-%, based on the sum of components b) to e), are used.

14. Fluorochlorohydrocarbon-free soft plastic, semi-hard or hard molded polyurethane body with a cellular core and a compressed edge zone, producible according to one of claims 1 to 13.

15. Use of mixtures of at least one phosphorus-containing, carbodiimide-forming catalyst and at least one carboxylic acid and / or its anhydride as a blowing agent for the production of chlorofluorocarbon-free, soft-elastic, semi-hard or hard polyurethane moldings with a cellular core and a compressed edge zone.